Mayor Bloomberg didn’t waste any time endorsing a hefty admission fee for the over-designed 9/11 mu seum at Ground Zero.

“Well, the money’s got to come from someplace,” the mayor shrugged on his weekly radio interview.

Well, sure.

The museum — which won’t be ready for September’s 10th anniversary of 9/11 — is costing more than a half-billion dollars to build, with a projected $60 million in annual operating costs.

Add in the 9/11 memorial, and the price-tag likely will exceed $1 billion.

The contrast with the $8 million cost of the Vietnam War Wall — one of the most compelling pieces of memorial architecture in the nation — is stunning.

Joe Daniels, president of the museum’s operating foundation, told the City Council he needs to charge up to $25 per person as a “suggested donation,” or a flat $20 mandatory admission fee, to “generate revenue in line with other world-class museums.”

Well, the “world-class” part remains to be seen.

And, even so, it’s a grotesque fee for a facility meant to note the thousands of lives lost in the 9/11 sneak attack.

To Bloomberg, on the other hand, the museum is little more than just another New York tourist attraction.

“Given people pay 12, 15 bucks to go to the movies,” he argued, “if you have a nominal charge that helps pay the bills, I certainly have no objections to that.”

And proving that Bloomberg’s first instinct is to think like a billionaire philanthropist, he suggested that “people that gave all that money” — $400 million that’s been raised privately — “I think you can certainly say maybe they should be able to get in for nothing.”

“Maybe [you] can make the case for [9/11 victim] family members,” he added.

Really?

You think?

All of this could have been avoided had a more modest — dare we say more appropriate — project been undertaken to begin with.